An investigation by the BBC has found almost all fake Apple chargers sold online fail a basic safety test. 99 percent of devices failed, with only three out of four hundred passing.

The tests were conducted by the UK’s Trading Standards and involved firing a high voltage into the chargers. It found only three had adequate insulation for protection against electric shocks. The tests were carried out on chargers from multiple countries – eight in total – including the US, China and Australia.

Chief Executive of Chartered Trading Standards Institute Leon Livermore commented: “Counterfeit and second-hand goods are an unknown entity that could cost you your home or even your life, or the life of a loved-one,” he said.

The report urges consumers to ensure they buy plugs and chargers from trusted suppliers.

Apple itself has recently come out and said it’s making the fight against fake products a “major goal.” They also recently filed a lawsuit against a company selling fake chargers on Amazon.

You can read more about the tests and how to spot fake chargers on the BBC website.